In the principal aspect, the present invention relates to a fluid logic device and more particularly to a sequential inhibitor (NOT) fluid logic device.
It is often desirable to provide a sequential logic system to control pneumatically operated equipment, for example. Various fluid logic devices have been proposed and are disclosed in prior publications, e.g. Bouteille, Fluid Logic Devices, John Wiley and Sons. Additionally, many patents have issued which teach various devices and systems including the patent to Brandenberg for a NOT Device, U.S. Pat. No. 3,389,720 issued June 25, 1968, which is incorporated herewith by reference.
Fluid logic systems which provide for sequential operation such as a flip-flop system are very complex if conventional control hardware and techniques such as disclosed in Boutille and the Brandenberg patent referenced above are utilized. Complex systems, such as disclosed in the patent application identified by Ser. No. 63,923, filed Aug. 6, 1979, entitled "Multiple Element Fluid Logic Controls", Brandenberg, inventor, require a multitude of logic elements in order to provide the desired sequential operation. To reduce the number of logic elements in such systems, therefore, sequential fluid logic devices become desirable.
One of the desired fluid logic elements useful in sequential systems is a sequential inhibitor (NOT) device. Such a device would include a first or control input (a), a supply input (b) and an output (c). The output signal (c) generated as a result of flow of fluid through the supply (b) is inhibited by a control input (a) but only if the input (a) sequentially precedes the input (b).